Home-brewing fuel  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       

All Forums >> Glow Engines, Gas Engines, Fuel & Mfg Support Forums >> RC Fuels >> Home-brewing fuel
Page: <<   < prev  1 2 [3] 4 5 6 7 8 9 10   next >   >>  

Login
Message << Older Topic   Newer Topic >>
Home-brewing fuel - 9/28/2002 8:35:34 PM   
downunder-RCU



Posts: 1125
Joined: 12/27/2001
From: Adelaide, South Australia
Status: offline 		Well I can see why you might think the needle was sensitive if you're used to 30% nitro. You're probably using up fuel twice as fast as zero or low nitro which means the needle has to be opened a lot more. Plus nitro has a huge tolerance range between being too rich and lean which makes the needle less sensitive.

(in reply to volare)
       Post #: 51

Home-brewing fuel - 9/29/2002 8:33:56 AM   
rsieminski



Posts: 1406
Joined: 4/24/2002
From: Sarasota, FL, USA
Status: offline 		I worked on a spreadsheet today to help in the formulation, and cost effectiveness.
http://144.92.249.236/images/3154.xls

It should be pretty accurate, and maybe helpful.

Leaning out the idle screw a bit, seemed to hep with transition.


_____________________________

Tons of new content on my site:
[link]http://mywebpages.comcast.net/webmaster01/[/link]

(in reply to volare)
       Post #: 52

Printable ratio table - 9/29/2002 7:24:03 PM   
SDR-Hammer


 

Posts: 660
Joined: 9/9/2002
From: , MI,
Status: offline 		Since I came across this topic a couple days ago I started doing a little research for mixing my own fuel. For those that haven't visited the Klotz web site yet, they have a printable ratio table for mixing glow fuel.
http://www.klotzlube.com/products/rc/blending_chart.html

It took some cross-referencing but I was able to match what you guys are calling KL-100 and KL-200 with the names in the Klotz table

KL-100 = Super Techniplate (20% castor blend)
KL-200 = Techniplate

(in reply to volare)
       Post #: 53

Cool analyzer!!! - 10/1/2002 2:24:04 AM   
Capgains



Posts: 238
Joined: 2/27/2002
From: Klamath Falls, OR, USA
Status: offline 		Hey rsieminski,

Great analyzer. I copied it to my documents for personal use.

Going back through your posts, I noticed that you are trying to run with less/no nitro. What kind of engine are you using and why are you trying to do that?

Dan

_____________________________

Altamont Airport, Hair Care and Tire Center

(in reply to volare)
       Post #: 54

Home-brewing fuel - 10/1/2002 3:11:13 AM   
rsieminski



Posts: 1406
Joined: 4/24/2002
From: Sarasota, FL, USA
Status: offline 		Dan,
I have an os .15la, mag xls .25, os .32sx, mag xls .40, th .46, and a brand spankin new mag xls .91. I didn't want to spend the extra $ to buy 30% any more, so I switched to 15%. On the .32sx, flights went from 6 min to at least 9 min ( I never pushed it, could have been longer). I tried 10%, and flight time went to 12 min, full tank, to empty dead stick ( don't ask ). The difference was hardly noticeable in the air, especially when I removed the head shims. Low/no nitro can tolerate higher compression.
The mix I made was 2.5% nitro, and other than having to lean out both needles ( the need to adjust the low needle was not real apparent at first ). Otherwise, 14 min plus, easy. I didn't clock it, but it seemed just as fast.
The major advantages were: Little difference in RPM, 1st quality ingredients, way lower cost, longer flight times, and I did it myself.
--Rick

The .32 was outrunning the .46fx's when we were playing chase, just as it did before.


_____________________________

Tons of new content on my site:
[link]http://mywebpages.comcast.net/webmaster01/[/link]

(in reply to volare)
       Post #: 55

Home-brewing fuel - 10/1/2002 4:50:57 AM   
Capgains



Posts: 238
Joined: 2/27/2002
From: Klamath Falls, OR, USA
Status: offline 		Ohhhh!!! never thought of that. I usually run 10 or 15%, but just recently started running 20% in my YS. I guess it does drink it down a little faster.

I once tried to run FAI 0% in my OS 46sf and it ran like....... well it didn't run well at all. It got really hot too.

So you are saying that you have to lean it up compared to a higher nitro then? It seems that the highter in nitro you go, the less important the needle valve is.


Dan

_____________________________

Altamont Airport, Hair Care and Tire Center

(in reply to volare)
       Post #: 56

Home-brewing fuel - 10/1/2002 5:28:31 AM   
rsieminski



Posts: 1406
Joined: 4/24/2002
From: Sarasota, FL, USA
Status: offline 		Well, it's not really running lean. The needle valve needs to be screwed in further. FAI 0% I think has 20% all castor. That shouldn't make it run hotter, cooler I would think. Nitro adds oxygen to the mix, so more fuel can be burned in the same amt of time.

YS have to fun the expensive fuel. I don't know why, but all the guys run 20% min. They say any less and it just wont perform.

Yes the needle seems to be critical on low nitro. Just a click or two off of peak, and it's ready to go. I had to completely readjust all the settings on all the engines. But, now they run just as well, even cooler than before, and only a few hundred rpm less.


_____________________________

Tons of new content on my site:
[link]http://mywebpages.comcast.net/webmaster01/[/link]

(in reply to volare)
       Post #: 57

Home-brewing fuel - 10/1/2002 6:36:03 AM   
downunder-RCU



Posts: 1125
Joined: 12/27/2001
From: Adelaide, South Australia
Status: offline 		rsieminski....maybe we should team up and spread the word that nitro is a waste of money, even when it's as cheap as it seems to be in America

But to put things straight about why an engine flies longer with low or zero nitro, it's all to do with the fuel/air ratio difference between methanol and nitro (plus the fact that nitro releases extra oxygen). So let's start by talking about your car burning gas (or petrol as it's called in the real world ). For best power it needs to be about 12.5:1 (that means 12.5 pounds of air for every 1 pound of petrol burned). Now fill the tank with methanol and you'll have to double the size of the carb jets because methanol needs a ratio of about 6.5:1 which means you need nearly twice the weight (and fuel flow) for it to burn properly. So your car that used to give 20mpg now does 10mpg. However, methanol will work with a ratio anywhere between 6.5 and 4.5:1 so you could be down around 7mpg!

Now let's go to model engines. Nitro needs a ratio of 2.5:1 which puts it somewhere around twice the volume needed for methanol (I'm saying volume but in fact it's weight). But this 2.5:1 is the LEANEST mix it will burn properly at. It will burn just as well 5 times richer or even more! Imagine a fuel/air ratio of 0.5:1 compared to methanol at even 4.5? That's 9 times more weight of nitro than methanol. Of course, when you mix the two then you have different air/fuel requirements depending on what % nitro is added.

This probably sounds a bit confusing but I can't think of an easier way to explain it. But as rsieminski pointed out, you're not really running leaner when you drop the nitro content...all you're doing is adjusting the flow of fuel to get the correct air/fuel ratio.

(in reply to volare)
       Post #: 58

KLOTZ mix table - 10/1/2002 8:15:28 AM   
Dave Harmon


 

Posts: 108
Joined: 7/23/2002
From: Sperry, OK, USA
Status: online 		SDR....be careful with that table you got off the KLOTZ site. I noticed that they have some errors on the % vs ounces calculations.
I mean that for a certain %, they are showing the incorrect quantity in ounces. The table is fine to use....after you correct it!
Dave

_____________________________

Mix Your Own Fuel....It's Easy!

(in reply to volare)
       Post #: 59

Fuel Mixtures etc. - 10/1/2002 9:50:21 AM   
Dave Harmon


 

Posts: 108
Joined: 7/23/2002
From: Sperry, OK, USA
Status: online 		Here is my experiences re % of oil & nitro vs engine mfg....
oil nitro
K&B/Veco .61 20 15 minimum for good transition & idle
K&B .40 " " " " " "
K&B Sportster .61 does not matter what you use it still won't run
Cox .049/.051 25 castor only, 30 nitro same as Cox fuel
Fox .35 no bearings 29 5 same as 'Dukes Fuel' good perf
Rossi .60 17 5 screams on this, lousy on zero nitro
Rossi .40 18 5 " " "
OS .32 helicopter 24 30 Klotz HeliGlow good rich run & trans
YS .61 20 20
YS .45 20 20
YS .120 all 20 20
YS .140FZ 20 20
YS .140L 24 30 Klotz HeliGlow/CoolPower Heli 30%
YS DZ 24 30 " "

Different engines require different fuel....especially all YS engines.
The closed loop fuel system of the YS models require the viscosity and nitro content to be in a range which will fit into the calibration window of the carburetor and regulator or else they are difficult or impossible to adjust properly. The above percentages are an absolute minimum for reliable operation except the 140L will run ok on 20x20 also. The YS engines are high performance therefore cost is ignored for maximum power and reliability. Power never ever came cheap and I don't expect it ever will, however, the cost of the nitro can be minimized by buying in larger quantity. I pay $40 for 1 gallon....$27 for 5 gallons...so I buy 10 gallons just in case the guy changes his mind next time!
Glow plugs are K&B1L idle bar for the K&B engines.
Rossi engines use Rossi #4 or #5.
OS .32 uses OS#8.
YS 2 strokes use Enya #3 or HobbyShack Performance #3 (only)
YS 4 strokes use OS F only.

Downunder said...

>This probably sounds a bit confusing but I can't think of an easier way to explain it. But as rsieminski pointed out, you're not really running leaner when you drop the nitro content...all you're doing is adjusting the flow of fuel to get the correct air/fuel ratio.<

True, however, there ain't no free lunch here.....natch, with zero nitro there is much less power (rpm) so there is a tendency to set the needle valve too lean causing overheating and I suspect the added sensitivity of the NV may cause a lean run in the air, even if the tank is properly located.
When I started flying Pattern 17 years ago, the engine to use was the Rossi 60 RE with in flight needle adjustment. They ran really good, however, I tried to use zero nitro and was melting the exhaust system. This was due to the sensitivity of the needle and was requiring resetting the needle in flight. Adding just 5% nitro completely fixed everything. Iv'e never actually seen ANYONE use FAI fuel (no nitro) successfully on any engine. This is not to say that it is not being done in Europe or elsewhere but if it is, I suspect the user is accepting operational problems as an offset to the high cost of nitro outside the USA.

Rick....what you might try with your engines is to run them on zero nitro and see what happens, then start adding nitro until they operate correctly. I see that you used 2.5% so I assume that you like it there. If the NV is too sensitive, add some more nitro and keep doing that till it works. You are using a wide range of engines so the oil & nitro content will probably be different. Generally, if you have the proper plug (I like hot plugs) there will be little or no change in rpm if you remove the glodriver at idle.
If it slows down the plug is too cold or there is too much oil, assuming the idle mixture is set correctly. Generally, for sport 2 & 4 strokes, 17% oil is a good place to start.
Never use castor in any fuel with todays engines. Above, I mentioned straight castor with the Fox .35. That is because there is no bearings on the shaft and they are set up very loose. They also have a different type of lapped piston/sleeve setup and all this really requires a very thick fuel to seal up everything. They run very well when used this way. For those of you that are using Klotz KL 100, castor oil just ain't needed and WILL carbon up your engine and the castor will crud up everything that gets hot...this is double true on 4 strokes. The exhaust valve and exhaust system will actually plug up to the point that the engine performance will suffer drastically...believe it!

Regards to All
Dave

< Message edited by Dave Harmon -- Oct 1 2002 5:09AM >

_____________________________

Mix Your Own Fuel....It's Easy!

(in reply to volare)
       Post #: 60

Home-brewing fuel - 10/1/2002 1:26:49 PM   
DerFly



Posts: 229
Joined: 3/11/2002
From: sydney, AUSTRALIA
Status: offline 		[QUOTE]Iv'e never actually seen ANYONE use FAI fuel (no nitro) successfully on any engine. [/QUOTE]

[QUOTE]Never use castor in any fuel with todays engines. [/QUOTE]

I wonder what the guys that fly FAI Pylon and FAI Control Line Speed are doing wrong?

(in reply to volare)
       Post #: 61

Home-brewing fuel - 10/1/2002 4:51:41 PM   
rsieminski



Posts: 1406
Joined: 4/24/2002
From: Sarasota, FL, USA
Status: offline 		The lower the nitro, the cooler the engine will run. If the engines on no nitro were melting some component on the engine, than the NV was set wrong, or there was too little oil in the mix. There is no mystery, synthetics will burn up way before castor will. Yes it may cause a litle more gum, than the synthetics, but break them down and clean them once a year(like you should any high performance engine), and they'll last years. Castor makes engines run cooler, by spuwing that oil all over the plane. That's what carries away the heat. Methanol has almost twice the latent heat of evaporation. This means it will carry away with it more heat than a higher mix of nitro, net resut is that it runs cooler. You can regain back most of those 2 or 300 rpm, by increasing the compression ratio. The pylon racere use only no-nitro/castor fuel. They avg over 130 mph. A little nitro gives you some slack with the NV, but it's not really necessary.


_____________________________

Tons of new content on my site:
[link]http://mywebpages.comcast.net/webmaster01/[/link]

(in reply to volare)
       Post #: 62

Home-brewing fuel - 10/1/2002 5:50:10 PM   
rsieminski



Posts: 1406
Joined: 4/24/2002
From: Sarasota, FL, USA
Status: offline 		I speak only about the racers at my club, I don't know elsewhere. I also got to thinking, the hot or hotter glow plugs, combined with high nitro compound the problem of heat. Low nitro/hot plug, high nitro/cooler plug.
I was talking to the sprint car mechanic, last week when I got my methanol. I asked him about getting nitromethane, he said, very simply "most clubs don't allow it and the cars run hot, so we don't carry it". He did point me in the direction of the guys who do carry it, though.


_____________________________

Tons of new content on my site:
[link]http://mywebpages.comcast.net/webmaster01/[/link]

(in reply to volare)
       Post #: 63